Grinder



Sept. 19, 1950 R. l.. scHuHMANN ETAL 2,522,643

GRINDER Filed May 20, 1946 5 Sheets-Sheet l Sept 19 1950 R. L. scHUHMANN ETAL 2,522,643

GRINDER 5 Sheets-Sheet 2 Filed' May 20, 1946 3 w n w Sept- 19, 1950 R. 1 scHUHMANN ET A1. 2,522,643

GRINDERv 5 Sheets-Sheet 5 Filed May 20, 1.946

` Sept 19, 1950 R. scHUHMANN ETAL 2,522,643

GRINDER Filed May 20, 1946 5 Sheets-Sheet 4 Sept 19, 1950 R. scHUHMANN ETAL 2,522,643

GRINDER Filed May 2o, 1946 S sheets-sheet 5 w www Patented Sept. 19, '1950 UNITED STATES PATENT OFFICE 2,522,643 GRNDER Richard L.- sehuhmann, Louisville, Ky., and inea-v eric C. Rudolph, New York, N. Y., assignors to American Duplex Company, Louisville,A Ky., a' corporation of Kentucky Application May 2o, 1941s, serial No. `670,976

(c1. anges) 1 Claim. 1

The present invention relates to cereal grinding machines. While not limited to use in grinding coffee, it is of particular utility in that applin cation and is so described herein.

In recent years progressive merchandisers have realized that a properly constructed coffee grinder not only performs the basic function of grinding coffee but also actually sells coffee. Marketing studies have demonstrated that such a coffee grinder is a sales builder, not only 4for coffee, kbut for other items in the retail establishment. It is therefore highly desirable to provide an improved, more reliable and accurate coifee grinder and to eliminate sources of service troubles and consumer complaints.

Coffee is presently sold in various grinds of which the major types are "Extra-fine, Vac, Fine, drip, Medium Perc and Coarse Pot, hereinafter referred to as Vac, Drip, Pero and Pot The most serious complaint registered by customers against conventional coffee grinders is that they often do not deliver coffee of the grinds ordered. Variousl attempts to solve this problem have been made. A primary object of our invention contemplates the providing of an improved coffee grinder which positively assures the correct grind and which reects a radical departure from other devel'opements addressed to the solution of this problem.

We solve this problem by providing a simple grind-control mechanism having a set of push buttons, each adapted when depressed to set the grinder fora different grind. When any one is depressed the operation of the mechanism is such as to release the others. Additionally, We provide an arrangement whereby stopping of the grinder motor at the Sametime places the grinder in such a condition that the appropriate one of the push buttons must be depressed and the grind positively selected before the grinder will operate in filling the next order. l

It is impossible for an operator jof our `grinder to lill one coffee order, stop the grinder, and inadvertently or carelessly to ll the next order with the same grind setting, as so often happens when using prior-art grinders, much to the chagrin of customers. First, our vgrinder will not operate until a grind is deliberately and consciously selected. Second, our grind control mechanism includes dual controls and can be operated either by a store clerk on one sidel of a counter or by 'a customer on the other. rIrhird, if operated by the clerk, the customer has 'a visual check on thegrind chosen by the clerk. Thus We reduce the human 'factor of error to vzero and eliminate a prime source of consumer complaints. Further, We provide a reliable self-service device which stirs consumer interest, is simple in operation and can be properly and accurately operated by almost anyone without previous training or experience.

A second source of consumer grievances is the lack of uniformity of grind so often characteristic of cereals processed by prior-art grinding devices. Customers demand, and have a right to insist on, quality and uniform consistency to the last grain. One of the -major causes of such lack of homogeneity is the positioning of the grinder elements in such a fashion as to permit non-uniformity in burr-teeth alignment and as to introduce wear and mechanical eccentricities. Another object of our invention embraces the providing of an improved grinder having grinding elements positively positioned in concentric relation and havingburr teeth uniformly aligned.

We solve the lastmentioned problem by providing in a cereal grinding mill a rotatable shaft, a pair of concentric burr carriers, one of the carriers being secured for rotation to the shaft and the other lof the carriers being apertured to provide a bearing for the shaft. Mating concentric burrs are individually mounted on the car riers, the burrs being rotatably movable with respect to each other but maintained in radial registry by the shaft and bearing.

Another source of dissatisfaction arises from incomplete mixing of cereal and chaff. A further object of our invention is to eliminate this difficulty.

The major expense items in operating prior-art grinders are grinder-element replacement and the llabor cost and lost-sales costs thereby occau sioned. In accordance 'with objects of our inven tion we provide a grinder in which grinder-elem ment Wear is reduced to a minimum and in which worn burrs can be replaced quickly, easily, and economically, thus assuring continuity of operation and maximum sales return on equipment investment.

"A'Ihe above and other advantages and capabiliu ties -of your invention vvill be apparent from a de tailed description of the accompanying drawings in Whibhrwe have illustrated a preferred form of our invention, but the construction therein shown is to be understood as illustrative and 4not as defining ther-limits of our invention.

In the drawings:

-1 is a perspective view, partly in section, of a coffee grinder including a novel adjustable mechanism --of grinding `elements and a novel grind-control mechanism provided in accordance with our invention, the lid and cover of the grinder being removed;

Fig. 2 shows a fragmentary radial section through the burrs included in the Fig. 1 embodiment;

Fig. 3 is an elevational View, partly in section, taken on a, plane parallel to the plungers illustrated in Fig. 1 and showing the display shelf, housing, lid and coffee-discharge spout;

Fig. 4 is an elevational View, partly in section, taken on a plane perpendicular to the plane of Fig. 3 and showing in outline the location of the display Window;

Fig. 5 is a top plan view o-f the Fig. l embodiment, the lid and top of the housing being removed;

Fig. 6 is a perspective View of the stationary burr carrier and the lever means for axially displacing it with respect to the rotating burr carrier;

Fig. 7 is a detailed side elevational View, partly in section, of the push-button grind-control assembly;

Fig. 8 is an exploded view of the detent arrangements shown in Fig. '7;

Fig. 9 is a front view, looking in a direction through the springs, of the inner clamp member for ganging the upper detent springs of the grind control; and

Fig. l0 is a rear View of the outer clamp member for ganging the lower detent spring portions.

Referring now specically to Fig. 1 of the drawings, there are shown; a hopper II into which a cereal, say coffee, to be ground is placed; an adjustable grinding mechanism comprising a pair of burrs I2 and I3 for grinding the coee in accordance with a selected grind; a lever means generally indicated at I4 for axially displacing the stationary burr with respect to the rotary burr, thereby to adjust the grind; another lever means 43--53 for varying the position of the first-mentioned lever means; a grind-control mechanism comprising a plurality. of manually operated push buttons I6, I1, I8, I9, and 20 (Fig. 4) for ordering a particular grind; an electric motor 2I for driving the rotary grinding element; switching means 22 for removing the setting of the control mechanism when the driving motor is stopped, and thus assuring a deliberate choice z of grind before a succeeding order can be iilled; and a grasping means generally indicated at 23 for assuring control of the grind-control mechanism by the selected push button only.

The overall operation of the Fig. 1 embodiment is very simple. The indicia, Extra Fine Vac, Fine Drip, Medium Pere, Course Pot, and Change are inscribed on the push buttons I6, I'I, I8, I3, and 23 respectively. The clerk pours the contents of a bag into hopper I I. The customer pushes the appropriate one of buttons I6, I'I, I8 or I9, according to the grind desired. The motor 2| automatically starts and ground coffee is discharged from spout 24 (Fig. 3). When the order has been lled, the clerk pushes button 20 and that operation causes the push button for the selected grind to be released. I-Then the grinder is in a neutral position and is incapable of supplying coffee of any particular grind until a succeeding order is placed by pushing the appropriate one of the grind-selecting push buttons. These mechanisms are suitably housed and supported in a manner specifically described hereinbelow.

Referring now to Fig. 3, there are shown the details of the adjustable grinding elements. The motive-power unit 2I has a shaft 25. An annular shoulder 26 is formed by a smaller-diameter extension of the shaft. Rigidly mounted on the shaft at this shoulder and keyed thereto at 2'I is a rotating burr carrier 28. This carrier is formed with an annular shoulder 29. Secured to the carrier by a plurality of screws 3D is a demountable burr I3. Carrier 28 and burr I3 comprise the rotating grinder element. In accordance with one feature of our invention, this burr carrier is provided with combs 3 I, located radially outwardly from the burr teeth. These combs perform an important function in mixing the chaff and ground cereal expelled from the outside row of burr teeth.

A mating burr I2 is mounted on a stationary burr carrier 32 by screws 33. Burr I3 is rotated with respect to burr I2 by the action of motor 2I. Burrs I2 and I3 are maintained in radial registry and'they, as well as shaft 25 and burr carriers 28 and 32, are maintained in accurate concentric relationship by reason of a bearing for shaft 25 which is provided on burr carrier 32. To that end. carrier 32 is formed With integral Webs I5, which concentrically position an integral hub 34. Fitted within this hub is a self-lubricating bushing 35.

The stationary burr carrier 32 is constructed with an annular shoulder 36, machined concentric with the bore of bushing 35. The stationary burr I2 is aligned on the shoulder 36 and demountably secured to the burr carrier 32 by means of screws 33. The bushing 35 has sufdcient clearance with respect to shaft 25 that the entire stationary unit comprising the elements I2, 35, 32, 34, 33, I5, may be displaced axially with respect to the rotating grinding element I3, 28, thus affording adjustability for purposes of grind control. The elements I 2, 32 are hereinafter referred to as the stationary grinding elemen It is of course within the spirit of our invention to adjust the axial position of grinding element I3, 28 instead of that of the grinding element I2, 32 and We select grinding element I2, 32 as the f adjustable element in our preferred embodiment for purposes of illustration.

Important results are obtained by the construction so far described. In the first place, the burrs are mounted for ready axial adjustment and are at all times maintained in radial registry by the i shaft 25 and bearing 34, 35. The forming of the carriers with integral annular shoulders assures concentric relation of the burrs. The feature by which the burrs are demountably secured to the carriers permits immediate replacement of worn burrs with a minimum of delay and labor cost. The combs thoroughly intermix expelled ground material and chai. Most important of all, the spacing between the mating edges of the burr teeth is uniform throughout the circumference of the burrs. Burr wear is thus minimized and consumer good-will is cultivated. Moreover, the annular shoulders '29 and 33 assure proper alignment of replaced burrs and save the expense of delicate aligning operations.

The Fig. 1 embodiment includes a grind-control mechanism for adjusting the stationary grinding element. This mechanism comprises a lever generally indicated at I4. It consists of two arms 31 and 38 interconnected by a fork 39 (Fig. 5). This lever is pivotally fulcrumed by a set pivot 40, journaled in bearings 4I and 42. The set pin is secured by cotter pin 43. Each arm carries a lock nut 44 and an adjusting screw 45. The

zero settings of screws 45 determine, for any.

given selected grind, the depression of machine screws 46. These screws are normally biased outwardly by individual compression springs 41, each conned between the head of its associated screw 46 and grinder case cover 1|. Each machine screw 46 passes through a, hole in cover 1| and is screwed into the stationary burr carrier 32 as clearly shown in Fig. 3. Screws 46 are screwed into burr carrier 32 at diametrically opposed points. The arrangement of arm, lock nut, adjusting screw, machine screw and compression spring is the same on each arm. The action of the compression springs 41 and screws 46 is such as normally to lift the burr l2 so far upwardly as to render the grind indeterminate. Lifting or lowering of lever I4 and the consequent lifting or lowering of burr I2 determines the spacing between the grinding elements and the iineness of the grind.

Extending from fork 39 is a pin 48. The position of this pin is determined by a second lever means or crank comprising an arm 49, which :bears on pin 48, and an arm 56. The position of rotation of lever 49--56 is in turn determined by the push-button and plunger assembly now to be described.

The above-mentioned assembly is supported in a frame which consists of a front support 5|, a rear support 52, a lower brace 53, and an upper brace 54. These braces are employed to fasten the frame to legs 55 and 56. These and the other two legs 51 and 58 (not shown) support the grinder case 59 and are in turn supported by a base 60. Slidably mounted in bearings provided in the frame members 5| and 52 are a plurality of plungers 6|, 62, 63, 64 and 65, which individually carry push buttons I6, I1, I6, i9 and 26, respectively. Compression springs 66, 61, 68, 69

and 10 normally maintain the plungers in and urge them toward out or neutral positions.

The lever 49-50 is pivoted at 12 on rear support 52. Lever 56 consists ofv two side members 'I3 and 14, rigidly pinned to arm 49 at 15 and secured together at their lower ends by a screw 1'6. A tension spring 11 functions to return arm 50 to its neutral position and normally to maintain it there. It will be seen that when arm 50 is in its neutral position, pin 48 is so positioned that the distance between burrs |'2 and I3 is at a maximum. Depression of push button I6 and actuation of plunger 6| in response to an order for Vac coffee causes levers 49-56 to be turned through a, certain angle in a counterclockwise direction (looking at Fig. 1). Depression of push button I9 and actuation of plunger 64 in response to an order for Pot coffee rotates the lever 49-56 through a considerably lesser angle.. This operation is accomplished by providing on the plungers pins 18, 19, 86 and 8|, respectively, and the pins are so longitudinally located with respect to their corresponding push buttons that depression of button I6 causes' thev arm 49-56 to be turned through a certain angle and depressions of buttons I1, I8, andY I9 cause it to bey turned through progressively decreasing angles'. The degree of turning of arm 49-50 determines the amount of downward displacement of pin 48 by arm 49. Thus it will be seen that depressions of' buttons I6, I1, I6 and I9 cause the burrs to be adjusted for progressively increasing axial spacing and for progressively increasing coarseness of grind. On the other hand, when all of the plungers are in the neutral position, springs 41 make the grind indeterminate by increasing the 6 spacing between burrs l2 and I3 to an excessive degree.

`Each of the plungers 6|, 62, 63, 64 and 65 is provided with its appropriate one of rear control knobs 82, 83, 84, 65 and 86. The purpose of these knobs is to permit control of the grinder from either side of its case. Thus, when it is placed on a store counter, either a customer on one side or the clerk on the other side can set the grind or stop the driving motor. Thus the custemer is afforded a visual check on the operations of the clerk.

Plunger 65 carries a switch cam 81 which bears against a spring biased plunger on micro switch 22 and stops the driving motor 2| by opening an energizing circuit when button 26 is depressed. When the button is not depressed, the plunger is biased outwardly, closing that circuit.

In our grind-control mechanism, we not only have a plurality of plungers but we also provide a like plurality oi releasable retaining means. That retaining means which comprises spring portions 88 and 89 is associated with plunger 6| and is adapted to grasp and hold a detent 96, concentrically mounted on that plunger, when button I6 is depressed and plunger 6| actuated. Similarly, plungers 62, 63, 64 and 65 are operatively associated, respectively, with spring portions 6| 92, S33- 64, 85-96, and 231-98. Each of the spring portions is screwed. to the rear frame member 52. Spring portions 88 andv 68 are individually mounted and the other spring portions, such as 69,- 9| are mounted in pairs, each pair being punched from a single piece of metal.v

Each of the plungers. (for example, plunger 6|) is adapted when engaged by its individual one of thei retaining means (for example 86, 89.) to set the grinder for a selected grind and to release the other retaining means (for example 9|-92, 93-64, {i5-96., and 91-98) from the other plungers (for example 62, 63, 64, 65, respectively).

To this end, all of the upper detent spring portions 88, 9|, 93, 95 and 91 are ganged by an. inner clamp member |66 so that they move in unison. Similarly the lower detent spring portions 89, 92, 94, 96, 98 are ganged and have their free ends fastened to an outer clamp member IUI. The clamp members are apertured to permit the movement of the plungers. The other plungers 62, 66, 64 and 65 are provided with detents |62, |63, |04, |05, respectively. Each detent (for example detent |64) is adapted to advance between a spring pair (for example spring portions 95 and 96.). comprising a lower detent spring portion andan upper detent spring portion when its associated plunger (for example plunger 64) is' actuated, thereby to spread said spring portions (for example spring portions 95 and 96) and to release the other plungers (for example 6 I, 62, 63 and 65), said detent (for example |64) being so shaped as to be grasped by that spring pair (for example 95, 96) upon continued advance of that plunger.

When the button 20 is depressed, not only is the driving motor stopped but all of the other plungers 6| through 64 are at or are restored to their neutral positions. If any one of them is retained by its spring pair, it will be released by the operation of the grasping means (88--96, IDD-|05). When any one of the grind-control buttons is depressed and before the appropriate detent locks in the detent springs at the rear of the frame, these springs are compelled to ride over the advanced, enlarged surface of the detent and are thus spread, the upper spring portion being raised and the lower spring portion being lowered. Since all lower detent springs move in unison and since all upper detent springs move together, any other plunger which happens to have its detent locked by these springs is released and the return compression spring under the head of the front push button snaps the plunger to its original outward position. Additionally, when any one of the grind-control buttons (I6-I 9) is depressed,the motor reset plunger |55 is released, the switch cam 81 disengages the limit switch 22 and the motor circuit of the driving motor is energized. Conversely, stopping the motor by pushing in button 20 to break the motor circuit automatically releases all of the grindcontrol buttons (|6-I 9) and compels a new grind adjustment for each customer.

Thus it will be seen that our invention provides a grind control mechanism comprising a plurality of manually operative means (I6, 6|, 90), (I1, 62, |02), (I8, 63, |03) and (I9, 64, |04), each adapted when actuated to set the grinder for a different grind and means (88, 96, |00, |I) responsive to actuation of any one of said manually operative means for disabling the others of said manually operative means, whereby only the selected manually operative means determines the grind. We also provide an additional manually operative means (20, 65, which is adapted, when displaced in one direction and grasped by .that part of the grasping means which includes spring portion 91 and 98, to deenergize the motor 2| and to assure the return of all the other manually operative means to neutral positions.

The whole untary assembly is placed in a suit-- able housing |08 (Figs. 3, 4, and 5). This housing is provided with a lid |09 hinged at ||0. A display window I is superimposed over an aperture provided in the housing and is secured by appropriate fastenings I|2, ||3. A bag of coffee or other cereal displayed |I4 is placed on a suitable shelf comprising a shelf bottom ||5 and a shelf back ||6, located behind the display window.

In conclusion, we have provided a novel coffee grinder comprising in combination a power motor 2|, a pair of grinding elements (I3, 28) and (|2, 32) adjustable to determine the neness of grind, one of those elements (I3, 28) being rotated by the motor 2 I, pivoted normally neutral fork lever means (31, 38, 39, 40, 4I, 42, 43, 44, 45, 46, 41) for axially adjusting the other of said elements (I2, 32), a normally neutral crank (50, 12, 13, 14, 15, 16, 49) for positioning said lever means, and control means for turning said crank, thereby to control the grind, said control means comprising a supporting frame (5|, 52, 53, 54), a plurality of normally neutrally positioned plungers (6|, B2, 63, 64) slidably mounted in said frame, each of said plungers having a detent (90, |02, |03, |04) and being adapted when displaced from neutral to turn said crank by a diierent amount, a normally neutral plunger (65) having a detent (|05) and also slidably mounted in said frame and adapted when displaced from neutral to deenergize said motor 2|, and means (66, 61, 68, 69, 10, 88, 89, 9|, 92, 93, 94, 95, 96, 91, 98, |00, |0|) responsive to actuation to any onejof said plungers for returning the other plungers to neutral.

Secured to the rear of the housing is a tray holder |20, formed with an open back and having three pairs of shelves I2|, |23, |25, each of which is adapted to support a removable pan |21. Shelves |2||22, |23-|24, I25|26 are identical but are secured to the sides of tray holder |20 at diierent heights. Pan |21 is placed on shelf |2| when a three-pound capacity bag is employed to receive coiee from the spout, on shelf |23 when a two-pound capacity bag is used, and on shelf |25 when a one-pound capacity bag is used.

While we have shown and described what is at present considered to be a preferred embodiment of our invention, it will be obvious to those skilled in the art that various changes and substitutions of equivalents may be made therein without departing from the true scope of the invention, and it is, accordingly, intended in the appended claim to cover all such changes as fall within the true scope of the invention and without the proper scope of the prior art.

Having thus described our invention, We claim:

In an adjustable cereal grinder, a plurality of grinder elements and a grind control mechanism comprising a frame, a plurality of plungers individually slidably mounted on said frame, each of said plungers having a push button secured to one end thereof and a knob secured to the `other end thereof, whereby it may be displaced either by a customer on one side of the grinder or by an operator on the other side of the grinder, a plunger-engaging means, means cooperating with said plunger means for setting said grinder for a predetermined grind when any one of said plungers is displaced in one direction and locked by said engaging means, said engaging means comprising a plurality of ganged springs, one for each plunger, said springs being adapted collectively to be spread in response to displacement of said one of said plungers in said direction, thereby to release all other plungers, and compression-spring means bearing on said plungers for displacing each of said plungers in the opposite direction upon release -by said engaging means, whereby only the plunger actuated either by a customer on one side of the grinder or an operator on the other side of the grinder sets the grinder for the desired grind.

RICHARD L. SCHUHMANN. FREDERIC C. RUDOLPH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 215,658 Oberchain May 20, 1879 309,187 Blevney Dec. 16, 1884 1,206,716 Keller et al Nov. 28, 1916 1,704,754 Marvin Mar. 12, 1929 1,928,200 Faas Sept. 26, 1933 1,984,869 Farley Dec. 18, 1934 2,090,634 Meeker Aug. 24, 1937 2,128,226 Atwood Aug. 30, 1938 2,141,311 Meeker Dec. 27, 193B 2,187,102 Schuhmann Jan. 16, 1940 

